Five former employees of the convicted swindler Bernard Madoff have been found guilty of fraud. They were accused of helping Madoff conceal his multibillion-dollar Ponzi scheme from regulators and investors. This was one of the longest trials in the history of federal court in Manhattan. More than 40 witnesses took the stand. And NPR's Jim Zarroli joins me now to tell us about it. Hi, Jim.

JIM ZARROLI, BYLINE: Hi.

SIEGEL: What role did these five defendants play in Madoff's operation?

ZARROLI: These were people who worked in Madoff's investment advisory business. They had what you would call support jobs. Two of them were computer programmers. One of them, Daniel Bonventre, had the title of operations director. Two of them were called portfolio managers, though their function seems to have been more administrative. I mean, these were not people necessarily with a lot of training or experience in the finance world. Some of them didn't go to college but they were paid very well. Annette Bongiorno, one of the portfolio managers, made $342,000 a year, and she owned a $6.5 million condo in Florida.

SIEGEL: Now, the five defendants were convicted on 31 counts of fraud. What kind of evidence did the government put forward against them?

ZARROLI: Well, the star witness was Madoff's former chief financial officer. His name was Frank DiPascali. He has pleaded guilty to participating in the fraud. He was on the stand for a month and he basically incriminated each of the defendants. He would, you know, spell out how each one of the five did something to conceal what was going on. They created phony trading records, you know, they backdated trades. And they did this, he said, because they wanted to fool auditors and regulators and investors. And in some cases, they did this for a long time. The people who worked for Madoff tended to stay with him for years.

SIEGEL: And in their defense, how did the defendants respond to those allegations?

ZARROLI: Well, two of them took the stand, Annette Bongiorno and Daniel Bonventre. All of them, though, had the same basic defense. Yes, we may have done some of the things that we're accused of, but, you know, we were as much in the dark as anyone else. Madoff told us what to do. We didn't know it was illegal. Bongiorno said Madoff was like a big brother to her. She worked for him since she was 18. She never questioned him.

The problem for them is that under federal law, you can be convicted of participating in a conspiracy even if you did not fully understand the extent of what was happening, even if you just had a suspicion about what was going on. And that seems to have been, you know, enough for the jury to find these people guilty.

SIEGEL: Now, the five have several months to wait for sentencing. What happens to them now?

ZARROLI: Well, they ultimately could face decades in prison. Madoff himself is serving a 150-year sentence right now in a federal prison in North Carolina. Frank DiPascali, who I said was the star witness in this case and helped convict the five, is also going to prison, although he is likely to get a significant time off for cooperating with the government.